About one-third of adults in the United States have high blood pressure. A number of factors increase the likelihood of developing this condition.

Risk Factors That Can Be Changed

Several risk factors for high blood pressure are wholly or partly under your control. By making changes in your lifestyle, you can lower your odds of developing high blood pressure—and that, in turn, reduces your risk of having a heart attack or stroke.

A poor diet often is built around high calorie foods low in essential nutrients, including ones containing saturated fat, trans fat, and added sugar. This type of diet is detrimental to overall health. It also makes it easier to become overweight. Beyond that, for some individuals, eating too much salt (sodium) can cause the body to retain fluid, which drives up blood pressure. Getting too little potassium, a mineral that helps balance the amount of sodium in cells, adds to the risk.

Physical inactivity

Lack of physical activity increases the risk of blood vessel disease, heart disease, and stroke. It also makes it easier to put on unwanted pounds. In addition, when you are out of shape, it takes more effort for your heart to pump blood. This increases the force exerted on arteries, which can lead to high blood pressure.

Overweight or obesity

About two-thirds of adults in the United States are overweight or obese. Excess weight places added strain on the heart and raises cholesterol and triglyceride levels. In addition, the more you weigh, the more blood is needed to supply oxygen and nutrients to your body. The extra blood volume puts increased pressure on artery walls.

Excessive alcohol

Long-term heavy drinking can lead to irregular heartbeats, heart failure and stroke. It can also contribute to high triglycerides. In addition, having more than two or three drinks at a time triggers the release of hormones that increase blood flow and heart rate. This, in turn, can raise blood pressure as well as reduce the effectiveness of high blood pressure medication.

Smoking

Smoking is one of the leading causes of preventable death in the United States, and it increases the risk of having a heart attack or stroke. With each cigarette you smoke, blood pressure also shoots up by as much as 10 points and stays higher for up to an hour. If you constantly have a cigarette in your hand, that could keep your blood pressure elevated for much of the day. High amounts of secondhand smoke, environmental smoke, and passive smoking can also contribute to high blood pressure; it is best to avoid cigarette smoke as much as possible.

Stress

Severe stress can lead to a temporary but dramatic spike in blood pressure. Over time, this might contribute to high blood pressure, although that has never been conclusively proved. In addition, some people cope with stress by overeating, drinking too much, or smoking.

Caffeine

Even if you're healthy, caffeine can cause a short-lived but dramatic rise in blood pressure. The amount of caffeine in two to three cups of coffee can raise systolic pressure (the top number in your blood pressure reading) 3 to 14 millimeters of mercury (mm Hg). Your diastolic pressure (the bottom number) can be increased 4 to 13 mm Hg. However, this transient rise in blood pressure due to caffeine has not been shown to increase your risk of hypertension. The cause of essential hypertension remains unknown.

Prehypertension

Prehypertension is slightly elevated blood pressure that isn't yet high enough to be considered high blood pressure. About 25 percent of adults in the United States have blood pressure in this range. If prehypertension isn't addressed by changing the lifestyle factors mentioned above, blood pressure is likely to keep rising.

Risk Factors That Cannot Be Changed

Learning about risk factors that are beyond your control can also be beneficial. If you know you're at high risk, you and your doctor can keep close tabs on your blood pressure and start treatment at the earliest signs of trouble.

Age

High blood pressure can occur in people of all ages, including teens, children, and even babies. However, the risk rises as you get older, in part because blood vessels become less flexible with age. More than half of adults in the United States age 60 and older have high blood pressure.

Gender

Men and women are about equally likely to develop high blood pressure at some point in their lives. However, the comparative risk varies by age. For those under age 45 men are more likely to have high blood pressure than women. The proportion evens out in middle age. By age 60 and older, women are just as likely as men to have the condition.

Ethnicity

High blood pressure affects people from all ethnic groups. However, African Americans develop high blood pressure more often and at an earlier age, on average, than their white or Mexican American counterparts. In addition, compared to white Americans, African Americans are more likely to die prematurely from high-blood-pressure­-related diseases, such as coronary heart disease, stroke, and kidney failure.

Family history

Like height and eye color, a tendency toward high blood pressure can run in families. If your parents or siblings have high blood pressure, you're more likely to develop it, too

Risk Factors for Children and Teens

The risk factors for older children and teens are similar to those for adults. Boys are at greater risk than girls, and African American and Mexican American youth are more likely to develop prehypertension or high blood pressure than their white American peers. Other contributing factors in this age group include overweight or obesity, physical inactivity, and an unhealthy diet containing too much salt (sodium).

In young children and babies, high blood pressure is usually caused by another condition, such as a heart defect, kidney disease, hormonal disorder, or drug side effect. Premature birth and low birth weight also increase risk.